This invention relates to fluid displacement apparatus, and in particular, to fluid compressor units of a scroll type.
A scroll type apparatus has been well known in the prior art as disclosed in, for example, U.S. Pat. No. 801,182, and others, which comprises two scroll members each having an end plate and a spiroidal or involute spiral element. These scroll members are so maintained angularly and radially offset that both of spiral elements interfit to make a plurality of line contacts between spiral curved surfaces thereby to seal off and define at least one fluid pocket. The relative orbital motion of these scroll members shifts the line contacts along the spiral curved surfaces and, therefore, the fluid pocket changes in volume. The volume of the fluid pocket increases or decreases in dependence on the direction of the orbital motion. Therefore, the scroll type apparatus is applicable to handle fluids to compress, expand or pump them.
As the scroll type compressor unit includes moving parts such as means for imparting the orbital motion of a scroll member, it requires any lubricating system for lubricating the moving parts.
Although various improvements in the scroll type compressors have been disclosed in many patents, for example, U.S. Pat. Nos. 3,884,599, 3,924,977, 3,994,633, 3,994,635, and 3,994,636, such a lubricating system is not almost proposed.